如果不满足条件,怎么能不发生segue？

我想在场景之间进行条件segue,这样只有在满足条件时才会发生.问题是,当我点击激活此segue的按钮时,它会执行segue而不关心是否满足条件.这是代码:

@IBAction func goonbutton(sender: UIButton) {
    if textFieldRandomWord.text !=nil
    {
        performSegueWithIdentifier("firstsegue", sender: sender)
    } else {
        whateverLabel.text = "You didn't actually write anything."
    }
}

所以我希望segue仅在textFieldRandomWord!= nil时出现.任何帮助将不胜感激!

你想要做的是实现如下:

override func shouldPerformSegueWithIdentifier(identifier: String, sender: AnyObject?) -> Bool {

    if identifier == "WhateverYourSegueIsNamed" { // you define it in the storyboard (click on the segue, then Attributes' inspector > Identifier

        if textFieldRandomWord.text.isEmpty == true {
            print("*** NOPE, segue wont occur")
            return false
        }
        else {
            print("*** YEP, segue will occur")
        }
    }

    // by default, transition
    return true
}

我在这个相关问题的答案中可以看到我对这个伟大例子的回答